Just to add, maximum voltage varying per load should not be much since DX90 has such a low output impedance. For example, if you have a high output impedance and you use a low impedance headphones, you will get much less voltage than much greater impedance headphones.

Also the high output impedance lower the power output to the load.

Also for those folks with BA iems or customs with multiple BA drivers. Keep in mind of the crossovers, which the high output impedance would affect since crossovers have resistors in them. this will change the filter, and mess up what frequency range each driver would output. Moral of the story is, DX90 has very small output impedance, so it's good for multiple BA iems.

Not true. The buf634 has output current protection so will limit current regardless of voltage but that voltage will be greater into higher impedance. Since low impedance loads (more current) tend to be more efficient and high impedance loads less current demanding (more V) it could actually work out well in real world use. I suppose it could get caught out into rare loads but anything below clipping should be great with the DX50. More power doesn't sound better. It just plays louder.

The part about low output impedance not reacting as much to load is correct, below clipping.

Beats me but into high impedance, I suspect it will be high but something a bit less than the rail V. I don't think it's a rail to rail device. It doesn't really matter if it's playing things well in the real world.

The guy from that website clearly has no actual experience - as usual he is someone spouting an opinion based on something he himself has read and for some childish reason believes without the adult maturity to investigate for himself - slightly irrelevant but looking at the picture - yeah, I wouldn't burn in a pair of apple buds!

Im amazed at how different my DT 880's sounded after 50 hours burn in - i listened before, after 1 hour and other times - the sound signature totally changed :D

Also I really dont trust or understand someone who publically creates and posts on the www to try to prove a 'negative' - just comes from pride, anger & arrogance

He says there is not enough 'evidence' from audiophiles! - why would we waste precious time with 'Doubting Thomas's' when we are perfectly happy and content with our beautifully burned in Headphones and equipment - It takes a certain maturity and the capacity to sit down and quietly listen (concentrate) which many people don't have. as they say - Empty vessels make the most noise :)

The main point from the audiophile side almost always simply comes from their experience - 'facts' and science and graphs have no relevance compared to someones actual experience. Even if their experience was somehow wrong - so what, they are still going to carry on enjoying their delusionally better sounding equipment!

To be honest I have no time for the types of minds that seem desperate to cling to facts and graphs whilst avoiding actual experience - such tight babyish small minds.

Science = looking at thing with eyes and naming them - there is slightly more to life than that :D

In other news, the Chinese guy who did the DX90 measurements is apparently very famous, and is the founder of Head-Fi equivalent of China. I guess we can think of him as the counterpart of our very own beloved Jude.

So I think DX90 actually only does 2.17 Vrms and puts out 147mW into 32 ohms at max. I think Ibasso should just say this on their website to avoid confusion. Unless the unit he has is beta or is defective.

No wonder people did not like the amp section of the DX50, that thing is weak, weak, barely better than the line out of most DAPs.

In other news, the Chinese guy who did the DX90 measurements is apparently very famous, and is the founder of Head-Fi equivalent of China. I guess we can think of him as the counterpart of our very own beloved Jude.

So I think DX90 actually only does 2.17 Vrms and puts out 147mW into 32 ohms at max. I think Ibasso should just say this on their website to avoid confusion. Unless the unit he has is beta or is defective.

No wonder people did not like the amp section of the DX50, that thing is weak, weak, barely better than the line out of most DAPs.

Yeah the amp section of the dx50 is a bit weak but it doesn't matter to me when I'm just walking to class or something. When I do serious listening on the dx50 (on the train or something), I always carry around my uha-6s anyways. Looking forward to getting my tracking # though :D

The guy from that website clearly has no actual experience - as usual he is someone spouting an opinion based on something he himself has read and for some childish reason believes without the adult maturity to investigate for himself - slightly irrelevant but looking at the picture - yeah, I wouldn't burn in a pair of apple buds!

Im amazed at how different my DT 880's sounded after 50 hours burn in - i listened before, after 1 hour and other times - the sound signature totally changed :D

Who reads "the wired"? :). It would have been interesting if he included a link to the actual study. Not just saying something he heard from his neighbor which also heard from another.

Anyway, burning-in a new piece of electronic gadget is not just about expecting things to get better after couple hundreds of hours. You are actually stress testing your device to find any flaws as early as possible. Those who have done or been assembling their own PCs should know this.

I never doubted the measurement and the output of the DX50 is sufficient for it's intended use. Quantity doesn't equate to quality. If a device doesn't play loud enough for you without distress than get something else. The measurements of all those devices don't tell you enough to differentiate them sonically for over 95% of what will be used with them. They will sound different but it wont be because of power capability. One power measurement doesn't tell you the story. It's just a preface.

Im not much into specs talk. So what is your conclusion with the X5 Vs. Dx90 for very low ohm impedance ba drivers like the shure se846?

I heard already that the X5+se846 is a pairing from heaven...

Well... is raw power the only thing important to you?

If that's the case the X5 seems to give you more current, so go with the X5. It will give you quite a bit more mW.

I think the DX90 will have the better DAC section and more cleaner sound/more black backgrounds. Like Jamato says. I'm expecting a very layered soundscape with great seperation and clarity. The amp section also has lower harmonic distortion. So it's weaker but might be the better sounding unless you need that power?

This is my conclusion based on internet research. I will have both units in hand next week, but I don't own the 846, so... haha, but I can tell you how they are with my 3 headphones I own.

For reference 2.1 Vrms is what the AK240 gives you in balanced mode. The DX90 gives you almost 2.2 (rounding up ), and should be "fine" for most applications other than really heavy loads.